Tank then added his details from the cave perimeter search. “There are signs of movement down into the southern cavern. Looks like the entire team headed down that way.” He nodded in the cave’s direction for the benefit of the HAWCs. “Some of the steps are far apart, indicating some of the people were moving at speed. Also, there is evidence of dragging—couldn’t make out what, maybe supplies, maybe bodies.”

“Captain!” Alex was about to ask Tank a question when the nasal voice of Dr. Silex punctured the ring of soldiers and terminated their debrief. The lead scientist strode into the circle of soldiers and faced Alex.

“Captain Hunter, it’s no good, this area is a honeycomb of varying geologies and hollow spaces, and with the significant magnetic disturbance of the pole I won’t be able to get any meaningful readings. We need to move; you need to get us deeper.”

“Do you smell that, Dr. Silex? Doesn’t smell like oil to me.”

“Of course I smell it. Are you a petrobiologist? Or even a geologist? Captain, raw petroleum can contain a hundred different chemical contaminants; too many for me to explain to you here and now. If it offends you, put on your gas mask, but we need to get further into the cave. That’s an order, Captain.”

Alex ignored Silex’s officiousness and looked down into the coal black mouth of the southern cave. He did not relish the thought of taking the civilian party in there. There was something else besides a chemical contaminant—something biological about the smell. He could also hear faint liquid noises emanating from the cave depths that had all his special senses on guard. He would have liked to take the HAWCs in first and leave the scientists right here. However, without more information, all he had was a gut feeling and no concrete reason to stall them any longer.

“OK, we can follow the tracks deeper into the cave. This will also give you and Dr. Weir some more depth and shelter from the interference. Benson, you’re on communications relay and base camp coverage in the event whatever made those people run down into the cave makes us run back out. Johnson, take point; Tank and Mike, left and right flank; Takeda, rear point, no stragglers. Stay alert, stay in visual with each other.” The men nodded once.

“Everyone go to night scope and comms and give me a check.” All the HAWCs withdrew from their backpack another item of equipment. It was a small, elasticised piece of head gear with two hardened arms no thicker than wire, ending in a bulb at each end. One end extended down beside the mouth, the other just beside the ear. This allowed normal hearing to be unimpaired. Plug-in earpieces tended to reduce stereoaudic hearing and therefore lowered rapid determination of source of sound—fatal in combat situations. On the other side of the head, now folded down, was a miniaturised version of the ATN Patriot night scope—this clipped neatly onto the helmet. With a built-in infrared illuminator, it allowed vision in even total darkness.